1. Field of the Invention
The present invention relates to connectors for coaxial cables and related components and methods, including, for example, rigid coaxial cables such as those used for trunk and distribution lines in such applications as cable television and the like, and related components and methods.
2. Description of the Related Art
Of the various coaxial cable designs, each has shared elements, e.g., including an inner or center conductor surrounded by an insulating material, typically referred to as the core, and an outer conductor surrounding the insulating layer. In some coaxial cables, such as with flexible coaxial cables, the outer conductor comprises a braided conductive material. These flexible coaxial cables typically include an outer insulator material, sometimes referred to as a jacket, that surrounds and encases the outer conductor. In other coaxial cables, for example, rigid coaxial cable, the outer conductor is a solid, conductive material, and the outer conductor commonly constitutes the exterior of the coaxial cable, without any need for an outer insulator or jacket.
Coaxial cable connectors must firmly and securely connect the coaxial cable to a terminal. Moreover, it is usually desirable, if not necessary, to ensure that the connector provide a seal so as to avoid exposure or contamination of the interior of the connector to moisture, particulate matter, and/or other undesirable material to which portions of the connector and/or cable may be exposed.
One concern with some commercially available connectors is that the tightening of the connector during installation causes an undesirable twisting of the coaxial cable, leading to unwanted stress on the cable that can cause wear and/or malfunctions.
To address these concerns, some connectors include a gripping and/or sealing component, for example, such as a ferrule, to contact and grip the cable at its exterior, whether it be an outer insulator or jacket or an outer conductor in cable designs that exclude the jacket. This ferrule or like component grips the cable exterior so that the cable is firmly secured with respect to the connector, and so that infiltration of environmental substances such as those noted above can be limited or avoided. The gripping component typically is housed within a larger housing component that also forms a part of the connector.
An example of a commercially available connector for connecting a coaxial cable to a terminal is shown in FIG. 11. The connector shown in FIG. 11, generally designated as 200, comprises a back nut assembly 202, a main nut assembly 204, and a body 206. A coaxial cable end (not shown) is inserted into a distal end 210 of connector 200, at a distal portion of back nut 202. A conductive pin 212 extends from a proximal end 214 of connector 200, at a proximal portion of body 206. A ferrule 220 is disposed in the interior of back nut 202. Ferrule 220 contacts the exterior of the coaxial cable. A pair of compression rings 222 and 224 are positioned within back nut 202 at proximal and distal ends of ferrule 220, respectively. The proximal compression ring 222 retains the ferrule 220 in place in the interior of the back nut 202, while the distal compression ring 224 prevents the ferrule 220 from moving distally.
When such a connector is in a disassembled state, for example, as possibly provided when new and ready for use, the gripping component, e.g., the back nut 202, and in some cases the ferrule 220, may be provided as a separate component or components, thereby requiring separate handling, which increases the likelihood of being misplaced or lost. Moreover, during installation the ferrule must be correctly inserted into the housing and retained while the remainder of the connector is installed and tightened in place. Thus, the cable gripping component often is partly or fully responsible for twisting the cable, which can place unwanted stress on the cable and connector through its interaction and cooperation with the associated housing.
Accordingly, an object of the present invention is to provide a connector and related components and methods that facilitate efficient pre-assembly handling.
Another object of the invention is to provide a connector and related components and methods that limit or prevent unwanted twisting of the cable during installation.
Another object of the invention is to provide a connector and related components and methods that are relatively efficient and cost effective.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims.
To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, a cable gripping component is provided for gripping a coaxial cable. The cable gripping component comprises a housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area.
The cable gripping component further comprises a ferrule disposed within the interior channel for contacting the coaxial cable. The ferrule comprises an outer surface that includes a raised portion. The interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.
The weakened area may comprise at least one groove, and preferably a plurality of grooves, which preferably is or are disposed on the inner surface of the sleeve portion.
The cable gripping component also preferably comprises a compression ring disposed within the interior channel between the ferrule and the inner surface of the housing. Preferably, the ferrule comprises a beveled mating surface, and the compression ring comprises a beveled mating surface for mating with the beveled mating surface of the ferrule.
The ferrule preferably has a terminus that extends beyond the terminus of the housing. The ferrule also may be loosely held within the interior channel. The ferrule also preferably may be rotatable within the interior channel.
In accordance with another aspect of the invention, a connector is provided for a coaxial cable. The connector comprises a cable gripping component comprising a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area.
The connector further comprises a ferrule disposed within the interior channel for contacting the coaxial cable. The ferrule comprises an outer surface that includes a raised portion. Interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.
The connector according to this aspect of the invention also comprises a coupling component attached to the first end of the cable gripping component. Preferably but optionally, the ferrule contacts the coupling component.
The cable gripping component of this connector may further comprise a compression ring disposed within the interior channel between the cable gripping component housing and the ferrule. Preferably, the compression ring does not contact the coupling component. It is preferred that the ferrule and the coupling component have mutually mating beveled surfaces.
In accordance with another aspect of the invention, a method is provided for providing a cable gripping component for a coaxial cable. The method comprises providing a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel, wherein the inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area.
The method also comprises providing a ferrule comprising an outer surface that includes a raised portion, and inserting the ferrule into the interior channel. It further comprises crimping the sleeve portion to provide interfering engagement between at least a portion of the retention surface and the raised portion, whereby at least a portion of the ferrule is prevented from exiting the interior channel. It also may comprise inserting the ferrule into the interior channel so that the ferrule is capable of rotating within the interior channel.
The method in its preferred implementation further comprises providing a coupling component and attaching the coupling component to the first end of the cable gripping component.
In accordance with another aspect of the invention, a method is provided for attaching a connector to a coaxial cable. The method comprises providing a cable gripping component for a coaxial cable, wherein the cable gripping component comprises a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface is disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area. In accordance with this method, the cable gripping component further comprises a ferrule disposed in an interior channel of the housing. The ferrule comprises an outer surface that includes a raised portion, wherein the inner surface narrows from the weakened area to the retention area and at least a portion of the ferrule is prevented from exiting the interior channel by the retention surface and the raised portion of the ferrule outer surface.
The method further comprises positioning the cable gripping component on the coaxial cable so that the ferrule contacts the coaxial cable, and providing a coupling component and attaching the coupling component to the first end of the cable gripping component. In its presently preferred implementations, the method comprises providing a compression ring within the cable gripping component to contact the ferrule.